ISX Coolant Pressure...Videos

I have a ISX cm871 550 in a 2009 389, no emissions or egr. It has intermittently been pushing coolant out the expansion tank cap. It has a new pressure cap which did seem to slightly help for a bit. Today at full operating temp I opened the reservoir cap and of course lost some coolant and the pressure out, no bubbles coming up through coolant so I put the cap back on. Next I put a hose on the expansion tank cap nipple and ran it in to a bottle of water, I had a small amount of very small bubbles. I disconnected the intake to the air compressor and blocked it off with my hand, the bubbles were small for a few seconds but then became very large. I hooked the compressor back up and the bubbles continued to be very large. I took 2 videos to show. Is this a head/ head gasket issue or what else could it be? Engine runs great, no over heating, etc. Any help is greatly appreciated.

 

Egr is gone cooler is gone, when you say block both ports fo you mean the intake and line to air tanks?

 

Ahhh gotcha, I will do that and go from there. Thanks

 

Coolant looks good, no black gummy stuff.

 

I should also mention that on several occasions it would puke out a fair amount of coolant while sitting over night. Is this an indication of the air tanks pressurizing the cooling system through the compressor head? Or am I out to lunch on that? Also as to my videos with the bubbles coming out expansion tank cap port is that normal? I always thought it meant something was wrong but on my cat engines that was always right off the reservoir cap.

 

One other thing I noticed while bottle testing, when I pulled the Air intake line off the air compressor head there was air constantly puffing out that port from the compressor, shouldnt it only be sucking?